39 Weeks Pregnant in Months

If you’re 39 weeks pregnant, you’re 9.75 months and full term!

Baby at 39 Weeks Size

At 39 weeks, your baby is now folded into a plump, petal-soft prize, a bit bigger than a bowling ball.

39 Weeks Pregnant: What to Expect

Congratulations, your baby is officially full term! He’s 7-8 pounds, but his length hasn’t changed much since last week.

Full term means he’s ready for his grand entrance! At this age, your baby’s stomach is the size of a Brazil nut. Just an ounce or so will fill it, but within days it will stretch to the size of a tiny fist (able to hold 2 ounces…or a bit more).

Right after birth, many babies have a 4-8 hour alert period and then they need to sleep, often for the better part of the day. The next 1-2 days, hunger ramps up. And, the baby starts eating more at the bottle and sucking harder at the breast demanding to suckle every couple of hours. (Although, some babies—especially those with a bit of jaundice—need to be awakened and encouraged to eat.)

Fortunately, like little camels, most full-term babies are born with a pound of extra food and water in the body, So, even though your milk may take 3 or 4 days to “come in” most babies have a pretty good reserve. Your healthcare provider or lactation consultant will help you learn how to read the signs to know if your baby is getting enough: your breast suddenly feeling very full (after a couple of days), milk leaking a little from the breast, hearing your baby swallow when suckling, wet inner mouth, frequent wet diapers—with urine that is barely yellow, etc.

39 Weeks Pregnant: Symptoms

After gaining weight throughout your pregnancy, you may suddenly notice that you’re not packing on the pounds as quickly or even that you’ve lost a pound or two. With all that baby in your belly, there’s barely room for food.

The end is really in sight. But don’t place too much stock on your due date…it’s more like an estimate. Studies have found that due dates are often off by 5 days or more. And, if your pregnancy goes past 40 weeks, your doctor or midwife may recommend a few possible options:

The “Wait-It-Out” Approach

If all is going well, she may allow you to carry your sweet-but-oh-so-heavy baby all the way to 42 weeks.


You can opt for a “natural” induction technique or a medical induction.

There are a few natural methods floating around on the internet, like nipple stimulation or drinking castor oil. Nipple stimulation can bring on contractions and castor oil is a pretty strong laxative and may cause severe diarrhea and even dehydration. Bottom line: Always consult your health care provider before trying anything to bring on your labor.

Hospital induction is done under close supervision from your medical team. They will closely follow the baby’s heart tones (often with a fetal monitoring device) and you’ll likely be given something to “ripen” your cervix (causing it to soften and begin to open) and medicine to stimulate rhythmic muscular contractions of your uterus. Those contractions pull open the cervix—little by little—preparing the way for the baby.

Typically doctors use prostaglandin, in a gel or suppository, to start the process. If contractions don’t start and your water hasn’t broken, your doctor may then insert a very thin probe through your open cervix to break the membrane surrounding the baby and all your amniotic fluid; causing your “water to break.” Usually, contractions increase and labor progresses normally. (If labor is still moving too slowly, your team may recommend using IV pitocin to strengthen the contractions.

39 Weeks: Pregnancy To-Do List

  • Practice relaxation: No matter how you slice it—epidural or natural, C-section or vaginal—labor is stressful. Breathing techniques, meditation, hypnobirthing or yoga are great “stay calm” tools.

  • Fill up your gas tank...literally: You won’t want to stop for gas while you are in full-on contractions. So, always keep enough fuel in your car to get you to the hospital/birth center and back.

  • Visit the drugstore: Stock up on supplies to care for yourself after delivery, like overnight pads (no tampons or menstrual cups), numbing spray, a peri bottle, and a stool softener.

  • Pick up treats for your nurses: Nurses have tough jobs—giving so much to women in labor and new moms—your gratitude is really appreciated. A small treat, like cookies or chocolates is a sweet thank you.

  • Review your birth plan: Make sure to go over it one more time with your midwife or doctor and to print it (in triplicate) to share with all the members of the team you will work with in the hospital.

Pregnancy Myth or Fact

Having sex can start your labor.

Can what got the baby in there really get her out as well? The hard science on this is mixed: some studies say yes, some say no. Orgasm does involve the uterus, and prompts the release of oxytocin, which is also secreted during labor. Semen contains prostaglandins, which may help to soften the cervix. If your water hasn’t broken, and you are low-risk, it certainly can’t hurt. Worried that it might be unsafe to have sex in the third trimester? Dr. Harvey Karp addresses this question.

38 Weeks Pregnant | 40 Weeks Pregnant

About Dr. Harvey Karp

Dr. Harvey Karp, one of America’s most trusted pediatricians, is the founder of Happiest Baby and the inventor of the groundbreaking SNOO Smart Sleeper. After years of treating patients in Los Angeles, Dr. Karp vaulted to global prominence with the release of the bestselling Happiest Baby on the Block and Happiest Toddler on the Block. His celebrated books and videos have since become standard pediatric practice, translated into more than 20 languages and have helped millions of parents. Dr. Karp’s landmark methods, including the 5 S’s for soothing babies, guide parents to understand and nurture their children and relieve stressful issues, like new-parent exhaustion, infant crying, and toddler tantrums.

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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.